Anchoring device

ABSTRACT

An anchoring device is disclosed for mounting in a vertical hole in a horizontally disposed building member to secure a tension member from which a length of ventilation duct is suspended. The device comprises complementary wedge-shaped elements dimensioned to be received axially in the hole, one element being fixedly mounted with its base disposed adjacent the top of the hole and the other element being movably mounted with its base disposed near the bottom of the hole. The fixed element has a series of downwardly facing transverse teeth in its outer surface engaging the side of the hole and the movable element has a smooth outer surface engaging the side of the hole, each element having smooth parallel confronting surfaces inclined with respect to the axis of the hole for frictionally engaging a portion of the tension member when the movable element is driven upwardly with respect to the fixed element. In one embodiment, the elements are solid and the tension member is a thin, flat strip or wire. In another embodiment, the elements have U-shaped transverse cross sections with parallel legs, the confronting surfaces being formed on the legs and the tension member being a thin, flat strip frictionally engaged between the legs.

United States Patent [72] Inventor Georg Broberg Solna, Sweden [21]Appl. No. 19,272 [22] Filed Mar. 13,1970 [45] Patented Aug. 10, 1971[73] Assignee Aktiebolaget Svenska Flaktfabriken Stockholm, SwedenContinuation-impart of application Ser. No. 856,600, Sept. 10, 1969.

[54] ANCHORING DEVICE 6 Claims, 10 Drawing Figs.

{52] US. Cl 85/79, 52/39, 521698, 248/60, 248/317 [51] Int. Cl E21!17/02, Fl6b 2/00 [50] Field ofSeareh 52/704,62, 698, 39; 85/79; 248/317,17, 343, 58; 61/45 B [56] References Cited UNflED STATES PATENTS1,946,949 2/1934 Stagg .1 52/62 3,342,097 9/1967 Rocheleau... 85/793,451,304 6/1969 Taylor 85/79 Primary Examiner-Frank L. Abbott AssistantExaminer--Robert A. Schwartz Attorney-Howson and Howson ABSTRACT: Ananchoring device is disclosed for mounting in a vertical hole in ahorizontally disposed building member to secure a tension member fromwhich a length of ventilation duct is suspended. The device comprisescomplementary wedge-shaped elements dimensioned to be received axiallyin the hole, one element being fixedly mounted with its base disposedadjacent the top of the hole and the other element being movably mountedwith its base disposed near the bottom of the hole. The fixed elementhas a series of downwardly facing transverse teeth in its outer surfaceengaging the side of the hole and the movable element has a smooth outersurface engaging the side of the hole, each element having smoothparallel confronting surfaces inclined with respect to the axis of thehole for frictionally engaging a portion of the tension member when themovable element is driven upwardly with respect to the fixed element. Inone embodiment, the elements are solid and the tension member is a thin,flat strip or wire. In another embodiment, the elements have U-shapedtransverse cross sections with parallel legs, the confronting surfacesbeing formed on the legs and the tension member being a thin, flat stripfrictionally engaged between the legs.

Patented Aug. 10, 1971 2 Sheets-Sheet 1 FIGI.

INVENTOR) GEORG BROBERG WW ATTY S.

Patented Aug. 10, 1971 3,598,013

2 Sheets-Shut z FIG.6. FIG'Z INVENTORZ GEORG BROBERG ATTYS.

ANCHORING DEVICE The present application is a continuation-impart of mycopending application Ser. No. 856,600 filed Sept. 10, 1969 and entitledAnchoring Arrangement Preferably Intended for Suspending VentilationDrums and the Like.

The present invention relates to anchoring devices; and moreparticularly, the present invention relates to an anchoring device whichis primarily adapted for mounting in a hole in a building member tosecurely mount a tension member from which ventilation ducts and thelike are suspended.

At present, there is a tendency toward standardization of the design ofventilation ducts to provide prefabricated ducts which may beexpeditiously assembled at the location of their intended use forreducing installation costs. An obstacle to an even greater reduction ininstallation costs, however, is the amount of labor which is presentlyrequired to mount the ducts. One of the reasons for this is because theceilings and beams which carry the ducts in many structures are ofpoured concrete construction and must be drilled upwardly to acceptexpansion fasteners which mount specially designed suspension irons.Each hole is normally drilled larger than the size of the fastenerrequired for a particular load in order to enable the hole toaccommodate the expansion shield or plug which mounts the fastener. As aresult, additional drilling time through hard material is required, andsince the location of drilling is overhead, it is tedious and tiring forworkmen. Moreover, when the expansion shield is wood or lead and thefastener has threads, even greater amounts of time are required forworkmen to mount the ducts because of the time required to rotate thefastener and the frequent absence of sufficient space in which theworkmen may operate. It is also to be noted that the outer surfaces ofsome types of expansion shields may not provide an adequate lateralgripping action in side the mounting hole to enable the shield to safelyresist downwardly applied loads. In addition, even with the use ofadjustable suspension irons, the aforementioned fastening devices havemade it difficult, and in some cases impossible, for the ducts to beaccurately mounted at a predetermined elevation.

With the foregoing in mind, it is a primary object of the presentinvention to provide an anchoring device which may be used to effecteconomies in the installation of ductwork by reducing drilling labor.

It is another object of the present invention to provide an anchoringdevice which may be quickly installed in its mount ing hole without theuse of threaded expansion fasteners.-

As a further object, the present invention provides an anchoring devicewhich is inexpensive to fabricate by high speed production techniques.

It is a still further object of the present invention to provide ananchoring device which may be used with wires or thin strips cut fromwaste material resulting from the fabrication of ducts.

More specifically, the present invention provides an anchoring devicecomprising complementary wedge-shaped elements having a combinedcircular or polygonal transverse cross section dimensioned to enable theelements to be installed in a hole for clamping a narrow, elongated,metallic tension member such as a strip or wire between confrontingsurfaces of the elements when one element is displaced relative to theother. The elements are mounted in the hole to dispose the base of oneelement deep in the hole and the base of the other element adjacent theopening of the hole so that the confronting surfaces are inclined withrespect to the axis of the hole. The one element has a series ofdownwardly facing transverse teeth in its outer surface engagingthe sideof the hole and the other element has a smooth outer surface to enableit to be displaced upwardly into the hole for effecting a firmfrictionclamping action on the tension member.

These and other objects, features and advantages of the presentinvention should become apparent from the following- Ill descriptionwhen taken in conjunction with the accompanying drawings in which:

FIG. I is a partially sectioned perspective view of an anchoring deviceembodying the present invention, the device being mounted in a hole in aceiling from which a length of ventilation duct is suspended by means;of a flat tension member;

FIG. 2 is a side elevational view of the anchoring device of FIG. Ilooking leftward along the top of the duct;

FIG. 3 is a cross-sectional view taken along line 3-3 of FIG.

FIG. 4 is a view of an anchoring device similar to FIG. 2 butillustrating a round tension member clamped by the device;

FIG. 5 is a cross-sectional view taken along line 5-5 of FIG.

FIG. 6 is an exploded view of a modified embodiment of the anchoringdevice of the present invention;

FIG. 7 is a view illustrating the modified anchoring device of FIG. 6mounted in a hole;

FIG. 8 is an enlarged cross-sectional view taken along line 8-8 of FIG.7;

FIG. 9 is a cross-sectional view of an alternate manner for mounting aduct from an anchoring device embodying the present invention; and

FIG. 10 is a view similar to FIG. 9 of another alternate manner formounting duct frotn a pair of anchoring devices embodying the presentinvention.

Referring now to the drawings, there is illustrated in FIG. I, aventilation duct D which is suspended from a horizontally disposedbuilding member, in the present instance a concrete ceiling I. The ductD is adjustably mounted at a predetermined elevation with respect to theceiling I by means of a tension member 3, in the present instance athin, elongated metallic strip, looped at its lower end around an eye 7which is welded to the top of the duct D and looped and clamped at itsupper end by an anchoring device A embodying the present invention. Astamped-out buckle member 8 connects the free ends of the tension member3 to permit adjustment at the mounting elevation of the duct D. Ifdesired, the duct I) may be mounted with a tension member 33 surroundingthe duct and the buckle 8 disposed on one side thereof as illustrated inFIG. 9; or, the duct D may be mounted in close proximity to the ceilingl by two tension members 43 fastened to opposite sides of the duct bymetal screws as illustrated in FIG. 10.

In accordance with the present invention, the anchoring device Asecurely suspends the duct D from the ceiling 1 without requiringshielded threaded fasteners and correspondingly oversized holes. To thisend, the anchoring device A is mounted in a hole 2 in the ceiling I andcomprises complementary elements 4 and 5, each of which has awedgeshaped profile forming inwardly confronting surfaces 4' and 5'between which is clamped the upper end of the tension member 3. Theelement 4 is mounted with its base or larger end disposed deep in thehole 2 and its apex or smaller end ad jacent the hole-opening;corresponding portions of the element 5 are oppositely mounted in thehole 2. As may be seen in FIG. 3, each of the elements has an arcuateouter surface so that the transverse cross section of the device A isslightly less than the diameter of the hole 2 when the elements aredisposed with their inside surfaces 4 and 5' in face engaging relation.In order to increase the gripping action of the anchoring device A inthe hole 2, a series of downwardly facing transverse teeth 4 a areprovided on the outer surface of the element 4. Unlike the element 4,the outer surface of the element 5 is smooth to facilitate its upwarddisplacement into the'holes.

In use, the tension member 3 is bent back on itself at its upper end,and the element 4 is inserted in the hole 2 with its surface 4' engagingthe tension member 3. The outer element 5 is thereafter positioned asillustrated in broken lines in FIG. 2 and is driven upwardly by a hammerinto the full line position. By virtue of their wedge shapes, theelements tightly engage the side of the hole 2 and clamp the tensionmember 3 therebetween.

In a modified embodiment of the present invention, an anchoring device B(FIG. 4) is provided for clamping a ten sion member such as a round,preferably steel, wire 13. For this purpose, the anchoring device B haswedge-shaped elements 14 and 15, similar to the elements 4 and S. Theelement 14 has a longitudinally extending groove in its surface 14 andthe element 15 has a like groove in its surface 15'. The radius ofcurvature of each-groove corresponds substantially to the curvature ofthe wire 13. However, as may be seen in FIG. 5, the depth of the grooveis less than the radius of the wire in I order to prevent theconfronting surfaces 14' and 15 from engaging one another and therebyreducing or possibly eliminating the friction clamping action on thewire 13.

The embodiment illustrated in FIGS. 4 and S is installed in a mannersimilar to the FIGS. 13 embodiment; however, it is preferable for theterminus of the wire 13 to be bent at a sub stantially right angle toitself for engaging the top of the element 14. In this manner,additional safety is provided in the event that the downward load on thewire 13 should exceed the upward friction forces thereon. it is apparentthat the wire may be be bent back on itself like the element 3, in whichevent double grooves may be provided in confronting sur faces.

ln still another embodiment of the present invention, an anchoringdevice C which is adapted to be manufactured by low-cost mass-productiontechniques is provided. its may be seen in FlGS. 6-8, the device C issimilar to the aforementioned anchoring devices A and B and comprisescomplementary wedge-shaped elements 24 and 25 each of which has a U-shaped transverse cross section (FIG. 8) forming pairs of con frontingsurfaces 24 and 25 for engaging opposite sides of a doubled length of athin, flat tension member 23 disposed therebetween (See FIG. 7). Thetension member 23 extends laterally beyond the edges of the surfaces 24'and 25 and it has a widthwise dimension which is less than the diameterof the hole 22 in which the device C is mounted (FIG. 8). Like theelements 4 and 14, the element 24 has a series of downwardly facingtransverse teeth 24a in its outer surface which engage the side of thehole 2, and the element 25 has a smooth outer surface engaging the sideof the hole 22. In this embodiment, the teeth 24a are formed bydisplacing the web of the element 24 outwardly at selected intervals,which operation may be performed concurrently with the shaping of theelement 24 to thereby effect manufacturing economies.

The anchoring device C is installed in a manner similar to theaforementioned devices A and B. in the illustrated mounting, however, itis to be noted that unlike the tension. members 3 and 13, the tensionmember 23 terminates below the tops of the elements 24 and 25V Anadvantage is realized from disposing the tension member in this manner,since it permits some vertical adjustment of the mounting elevation of aduct by enabling the ends of the tension member to be displaced upwardlyin the hole during installation. If desired, the tension members 3 and13 may be similarly disposed in their respective anchoring devices torealize this advantage without substantially impairing theireffectiveness.

in view of the foregoing, it should be apparent that an anchoring devicehas been provided which. is inexpensive to manufacture and which may beinstalled in a labor-saving manner.

While preferred embodiments of the present invention have been describedin detail, various modifications, alterations or changes may be madewithout departing from the spirit and scope of the present invention asdefined in the appended claims.

What I claim is:

I. An anchoring device mountable in a hole in a building membercomprising an elongated tension member to suspend an object therefrom,and a pair of complementary elements engaging said tension member tosandwich the latter between said elements, said member and elementshaving a cross-sectional dimension less than he corresponding transversedimension of the hole to enable the elements to be inserted axially intothe hole, one end of each element having a transverse cross-sectionaldimension greater than the other end thereof providing a wedge-shapedprofile forming at least one planar confronting surface inclined withrespect to the axis of the hole and engaging the tension member, saidconfronting surfaces of the two elements being in registry on oppositesides of said tension member, only one of said elements having a seriesof teeth in its outer surface for engaging one side of the hole, theother of said elements having a smooth surface for slidably engaging theother side of the hole, the greater end of said one toothed elementbeing disposed inwardly of the hole to effect a friction clamping actionon the tension member by said two registering planar confrontingsurfaces of said elements when said other smooth element is slidinglydisplaced relative to said one toothed element inwardly of the hole,each of said elements comprising a metal channel piece with a U-shapedtransverse cross section, the legs thereof providing registering pairsof confronting surfaces, said teeth of said one element comprisingoutward displacements of the web of the as sociated channel piece, saidtension member being engaged between said pairs of confronting surfaces.

2. An anchoring device according to claim I wherein said tension membercomprises a thin, elongated metallic strip which spans across the legsof said channel pieces.

3. A device according to claim 1 wherein the longitudinal dimension ofsaid elements is less than the depth of said hole to leave open spaceabove said elements in which said tension member is bent with its bentportion above the ends of said elements in said hole.

4. A device according to claim 3 wherein said tension member is bentback upon itself and is clamped between the confronting surfaces belowthe ends of the elements.

5. A device according to claim 3 wherein said tension member is bent ata substantially right angle to itself and terminates above said elementsto engage the end of said one element.

6. A device. according to claim 1 where said tension member terminatesbelow the upper ends of said elements between the confronting surfacesthereof.

1. An anchoring device mountable in a hole in a building membercomprising an elongated tension member to suspend an object therefrom,and a pair of complementary elements engaging said tension member tosandwich the latter between said elements, said member and elementshaving a cross-sectional dimension less than the correspondingtransverse dimension of the hole to enable the elements to be insertedaxially into the hole, one end of each element having a transversecross-sectional dimension greater than the other end thereof providing awedge-shaped profile forming at least one planar confronting surfaceinclined with respect to the axis of the hole and engaging the tensionmember, said confronting surfaces of the two elements being in registryon opposite sides of said tension member, only one of said elementshaving a series of teeth in its outer surface for engaging one side ofthe hole, the other of said elements having a smooth surface forslidably engaging the other side of the hole, the greater end of saidone toothed element being disposed inwardly of the hole to effect afriction clamping action on the tension member by said two registeringplanar confronting surfaces of said elements when said other smoothelement is slidingly displaced relative to said one toothed elementinwardly of the hole, each of said elements comprising a metal channelpiece with a U-shaped transverse cross section, the legs thereofproviding registering pairs of confronting surfaces, said teeth of saidone element comprising outward displacements of the web of theassociated channel piece, said tension member being engaged between saidpairs of confronting surfaces.
 2. An anchoring device according to claim1 wherein said tension member comprises a thin, elongated metallic stripwhich spans across the legs of said channel pieces.
 3. A deviceaccording to claim 1 wherein the longitudinal dimension of said elementsis less than the depth of said hole to leave open space above saidelements in which said tension member is bent with its bent portionabove the ends of said elements in said hole.
 4. A device according toclaim 3 wherein said tension member is bent back upon itself and Isclamped between the confronting surfaces below the ends of the elements.5. A device according to claim 3 wherein said tension member is bent ata substantially right angle to itself and terminates above said elementsto engage the end of said one element.
 6. A device according to claim 1where said tension member terminates below the upper ends of saidelements between the confronting surfaces thereof.